Current audio systems are generally designed and manufactured separately according to the particular features available on a specific model. Many of the various functions can now be controlled by software with a microprocessor rather than hardware. Some examples of such functions are station search functions, digital signal processing (DSP) functions, etc. Microprocessor control is possible and preferred in that a change from one set of functions to another is just a matter of a different software download or selection.
Existing radio bezels exhibit considerable complexity to account for different functions and to meet various market requirements. A given base model of radio may have several derivatives that have unique features associated with the buttons to implement different features such as clock versions, digital signal processing (DSP) features, noise reduction, etc. These features require unique plastic bezel assemblies with the associated button differences and thus result in high cost in audio systems due to the extra assemblies and manufacturing operations.
Consequently, in order to reduce costs, it is highly desirable and current practice to utilize common hardware, including the circuit board and microprocessor software for all radio models in a given product family, with only software variations. Some achieve these objectives by configuring the system so that the circuit board is strapped with resistors or jumpers that are interfaced to the microprocessor. These strapping resistors are configured to identify the configuration (for the particular model) that the microprocessor will run in its internal code to match the model features and bezel assembly. For those who employ this, current practices tie this resistor-configured board assembly to the intended plastic bezel assembly with assembly part numbers, computer tracking methods and bills-of materials. This requires considerable effort to track and maintain the parts and allows for possible errors. Further, the identifying resistors are added parts with associated material and manufacturing costs.
Thus, it is desirable to have an audio system which allows for various models with the same hardware, while allowing for different software base features to be changed for a given model of audio system based upon the corresponding model of bezel selected. Preferably, this will be accomplished with minimum cost and complexity concerns.